1. Field of the Invention
The present invention relates to a fingerprint verification system and a fingerprint verifying method for authenticating a person, in particular, to a fingerprint verification system and fingerprint verifying method using rotated angles of fingerprint data and a pre-designated rotated order thereof.
2. Description of the Related Art
In a conventional fingerprint verification system, when a fingerprint is registered and verified, a fingerprint of one finger is verified with all entries of fingerprint data that have been registered.
Mizukura Isao has disclosed xe2x80x9cIndividual Identifying Devicexe2x80x9d in Japanese Patent Laid-Open Publication No. 61-175865 (hereinafter this related art reference is referred to as first related art reference). According to the first related art reference, an input device such as a ten key pad for successively inputting registration numbers is disposed. When fingerprint data is registered, it is verified with successively assigned registration numbers that only the person who registers his or her fingerprint data knows. When the person is authenticated, he or she inputs the order of fingers and the assigned registration numbers. Thus, only fingerprint data corresponding to the registration numbers is read from the storing portion.
Suzuki Takao, Kawasaki Koji, and Kamiya Toshiharu have disclosed xe2x80x9cDetection Device for Fingerprint Picture Rotational Amountxe2x80x9d in Japanese Patent Laid-Open Publication No. 4-43469 (hereinafter, this related art reference is referred to as second related art reference). According to the second related art reference, a fingerprint is detected as a reference picture. The detected reference picture is overlaid with a registered fingerprint picture in such a manner that their center points match. In this state, angle differences of feature points of these pictures are detected. An angle difference that is most frequently takes place in those is output as a rotated angle of the reference picture. Thus, according to the second related art reference, the relative rotated angle of a verification picture and a registered picture can be accurately obtained without need to perform complicated calculations. As a result, according to the second related art reference, the fingerprint verification device can be compactly structured.
Igaki Seigo and Niizaki Taku have disclosed xe2x80x9cFingerprint Collating Devicexe2x80x9d in Japanese Patent Laid-Open Publication No. 5-242224 (hereinafter, this related art reference is referred to as third related art reference). Since fingerprints have two major features of xe2x80x9cunique for each personxe2x80x9d and xe2x80x9cno change in lifetimexe2x80x9d, it is said that they are the most effective means for identifying individuals. According to the third related art reference, a fingerprint picture is read and a feature picture is extracted therefrom as a window picture. The extracted picture is registered as an entry of a fingerprint dictionary. A rotating amount of the input verification picture against the center position of the fingerprint of the input reference picture is detected. The fingerprint reference picture and the window picture are verified. Thus, according to the third related art reference, even if fingerprint data is input in the state that the finger is rotated against the fingerprint data that has been registered, the person can be accurately identified.
Yokoyama Ken has disclosed xe2x80x9cFingerprint Matching Methodxe2x80x9d in Japanese Patent Laid-Open Publication No. 6-162174 (hereinafter, this related art reference is referred to as fourth related art reference). According to the fourth related art reference, for improving the system security, corresponding to conditions (such as a rotation and a distortion) of fingerprint data that is input, a search range of a plurality of verifying windows is adjusted. Thus, according to the fourth related art reference, the verification success ratio is improved.
Nakajima Hiroshi and Kobayashi Koji have disclosed xe2x80x9cPattern Collating Devicexe2x80x9d in Japanese Patent Laid-Open Publication No. 10-124667 (hereinafter, this related art reference is referred to as fifth related art reference). According to the fifth related art reference, even if there is a rotational deviation between a registered pattern and a reference pattern, they are verified. To do that, the pattern verification device according to the fifth related art reference comprises a registering Fourier pattern data generating means, a reference Fourier pattern data generating means, a combining means, an amplitude suppressing means, and a verifying means. The registering Fourier pattern data generating means performs an N-th dimensional discrete Fourier transforming process for a plurality of N-th dimensional patterns that are an N-th dimensional pattern as the registered pattern and N-th dimensional patterns of which the registered N-th dimensional pattern is rotated by predetermined angles. The reference Fourier pattern data generating means performs the N-th dimensional discrete Fourier transforming process for the N-th dimensional patterns and generates reference Fourier N-th dimensional patterns. The combining means successively reads and combines the registered Fourier N-th dimensional rotated patterns with the reference Fourier N-th dimensional pattern. The verifying means verifies the registered pattern and the reference pattern corresponding to the intensity of a verifying component area of the combined Fourier N-dimensional pattern.
However, the above-described related art references have the following problems.
According to the above-described related art reference, as a first problem, the primary object is to verify fingerprint data. In those related art references, information other than fingerprint data is not used. Thus, in comparison with a system using other information (such as rotated angles and a rotated order) as well as fingerprint data, the security level is low.
As a second problem, since registration numbers are used, a registration number input device such as a ten key pad as same as ten fingers is required.
According to the above-descried related art references, a finger is rotated so that registered fingerprint information matches reference fingerprint information. In other words, according to those related art references, a finger is rotated not from a view point of improving the security level.
The present invention is made from the above-described point of view. An object of the present invention is to provide a fingerprint verifying method and a fingerprint verification system using information (such as rotated angles and a rotated order) as well as fingerprint data so as to further improve the security level.
A first aspect of the present invention is a fingerprint verifying method for authenticating a person, comprising the steps of (a) inputting fingerprint data, (b) registering the input fingerprint data, (c) registering predetermined rotated angles of the fingerprint data and the rotated order thereof along with the input fingerprint data, and (d) verifying the input fingerprint data with the reference fingerprint data.
A second aspect of the present invention is a fingerprint verification system for verifying input fingerprint data with pre-registered reference fingerprint data is disclosed, the reference fingerprint data being data containing the fingerprint data, the pre-designated rotated angles, and the rotated order thereof, the system comprising a rotation data and reference fingerprint data storing portion for storing the reference fingerprint data.
According to the fingerprint verifying method and the fingerprint verification system of the present invention, it becomes difficult to forge a fingerprint and commit a fraud using a forged fingerprint.
With reference to FIG. 1, in the fingerprint verification system according to the present invention, a rotation calculating portion 21 calculates rotated angles and a rotated order of a plurality of entries of a fingerprint that are rotated by a plurality of any angles. The plurality of entries of the fingerprint are input from an input device 1. A rotation data and reference fingerprint data registration processing portion 22 stores the reference fingerprint data, the rotated order thereof, and the rotated angles thereof to a rotation data and reference fingerprint data storing portion 32. A rotation data and fingerprint data verification processing portion 23 verifies the rotated angles, the rotated order, and the fingerprint data of input data with those of registered data.
In such a manner, a fingerprint of a person to be verified is rotated at a plurality of desired angles. The rotated angles and the rotated order thereof are verified with fingerprint data and the correlated data is registered. When a fingerprint data verification process is performed, fingerprint data is input at the registered rotated angles in the registered rotated order. Thus, even if fingerprint data is forged, it is difficult to commit a fraud using the forged fingerprint data. Thus, the reliability of the system is improved.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of a best mode embodiment thereof, as illustrated in the accompanying drawings.